The present invention relates to a winding method and a winding apparatus of a coil including a plurality of coil layers.
As shown in FIG. 17, the applicant developed a coil 2 in which unit coil portions 23 formed by winding a conductive wire 22 in a swirl form are repeatedly placed side by side in the winding axis direction.
As a manufacturing method of such a coil 2, a method of continuously forming a first unit wound portion 25, a second unit wound portion 26, and a third unit wound portion 27 having different inner circumferential lengths from each other in the winding axis direction by winding a conductive wire in a swirl form as shown in FIG. 18 A, and continuously forming unit coil portions including the pluralities of unit wound portions 25, 26, 27 in the winding axis direction, so as to manufacture an interim product 20 of an air core coil, and then compressing the interim product 20 in the winding axis direction, pushing at least a part of the second unit wound portion 26 inside the third unit wound portion 27, and pushing at least a part of the first unit wound portion 25 inside the second unit wound portion 26 as in FIG. 18 B, so as to obtain a finished product 21 of the air core coil including a plurality of coil layers (three layers in the example of the figure) is known (Japanese Patent Laid-open Publication No. 2003-86438).
As a method of manufacturing the interim product 20 of the air core coil shown in FIG. 18 A, the method of using a stepped winding jig corresponding to a hollow shape of the interim product 20 (Japanese Patent Laid-open Publication No. 2003-86438) and an automatic winding machine for winding a conductive wire around a winding core member while changing a form of the winding core member for each wire winding step of a unit wound portion (Japanese Patent Laid-open Publication No. 2006-339407) are known.
However, with the method of using the stepped winding jig, a winding task is a manual task. Thus, there is a problem that production efficiency is bad.
With the automatic winding machine for winding the conductive wire around the winding core member while changing the form of the winding core member for each wire winding step of the unit wound portion, there is a problem that a configuration for changing the form of the winding core member for each wire winding step of the unit wound portion is complicated.